RAGBRAI Learn about the Land; Day 2, July 2008

Abstract

On today’s ride we continue riding across the Southern
Iowa Drift Plain. This landform region covers over 40%
of the state and comprises most of southern Iowa. Over
the last several million years Iowa was subjected to at least
seven glacial advances. The last of these older advances
occurred approximately 500,000 years ago. Since then
the landscape has been subjected to stream erosion and
from12,500-24,000 years ago was mantled with a thick
blanket of loess before
being further eroded.